This is a fine product, with all of the niceties that we've come to expect from QNAP, and, surprisingly attractive industrial design. For full functionality, you should connect it via Ethernet in addition to Thunderbolt even if you won't be accessing it via Ethernet. That way it can get FW updates and access the network time servers.I'm getting wirespeed transfers for large files over Thunderbolt, both up and down. There have been complaints about fan noise. My unit is quiet except for sustained wirespeed writes of over two minutes. Then the fans come on. They're noisier than the big slow fans that are probably in your workstation, because they have to fit in the small case. I don't consider it a problem.The sleds are slick, as are the M.2 adapters, and QTS Hero is a great OS.Addition after several weeks of usage:There are two big problems.The less severe is the fact that rebooting the NAS drops the Thunderbolt connection. The computer needs to be rebooted to reestablish it. This is not the case with my other Thunderbolt devices.The bigger issue is heat management. With 5 Corsair 8 TB M.2 drives with QNAP's heat sinks added, the SSDs overheat at the end of a 350 GB transfer at 1 GB/s.

I recieved this, installed my drives and set it up on my network. Eventually it asked to update which I allowed. Unfortunately it never came back up after the update started.Thinking this was a fluke I returned it and bought another which arrived a week later. The same thing happened.QNAP support said that it could only be fixed by RMA. They don’t have any way to reflash it locally.So be aware about a company that doesn’t test their updates and requires you to send it in at your expense when they break it with a buggy update.Updates:It came back from RMA scratched and with blood on it 🤢

TL;DR?Solid NAS, decent features - but a few quirks and items you need to plan for.The details?This machine solves the majority of MY specific needs.Those are:+ 2 or more ethernet ports.+ at least one 10Gbit RJ45 Ethernet+ 4 or more SSD, M.2 was mandatory, but E1.S compatibility was highly desirable.+ Thunderbolt 4 or better - for BOTH data transfer AND connection to my main machine.I connect to it from my main machine over Thunderbolt 4, and it acts as a gateway for that machine to my router. (That main machine is an M3 Max Macbook - so really appreciate that the QNAP routes the internet for my Mac over its NIC) The rest of my devices see it over the 10Gb connection as expected.I had planned on setting it up over Thunderbolt - but the QNAP utility did not discover it when connected this way as advertised.The typical online reviews and documentation all start their set up from the QNAP utility already having discovered the NAS. It only seems to function that way if connected via ethernet to a functioning network with DHCP available.What I eventually figured out is ... you can attach a monitor and keyboard for initial setup. Obvious in hindsight, but this option was documented nowhere.The initial console set up offers very few options, but it allows the QNAP utility to find it, and then you can log in to its web desktop interface, as documented in many places, and then things really start moving along.Once I got over that hurdle, all worked very well - except that the drives overheated a few times. The "optional" heat sinks are realy not optional at all for M.2 devices. I do hope that QNAP addresses this - they need a bit more space around the drives and slightly larger fans. Also the fan ramp up in the current hardware needs to "shift left" a bit to help avoid nasty warning alarms.(I should note that E1.S drives should both handle heat dissipation better and have higher temperature tolerances. - Alas I am not using any yet.)Fortunately I already have the heat sinks for this chassis on order as I anticipated this ... but I wanted to play before they arrived, so I take my share of the blame.Speaking of the alarms - they are loud and repetitive. You can disable them, but there was no option I could find to make them a bit less, well ... alarming. If you have this in your workspace they are too loud, even if you work with headphones. If you have it in a network closet or remote location, you will be dependent on messaging/SMS/email for alerts ... so they missed an opportunity to make this a more comfortable experience. Once I configured those notification systems, I silenced all alarms on this device.This was my first QNAP and QuTS Hero system, overall I am pleased. I do wish similar hardware was available with more OS options. (TrueNAS, UnRaid, Open Media Vault, etc.) I found the QuTS System to be a bit difficult to find stuff initially... but as I got used to the system of course it got easier. Plan on spending some time learning it to take full advantage of this device.The rating of 4 out of 5 stars is based on just a week or so of use. I can not speak to long term durability, reliability, or support yet.I took off 1 star because they didn't document the Thunderbolt connection and initial set up, and for the subpar thermal management. The alarm criticism is not affecting my rating, nor is my opinion of how hard/easy it was to find stuff as a new QuTS user.Looking forward to a next iteration - I am hoping for Thunderbolt 5, and if they could swap the 2.5g Ethernet for a 40 or 100G SFP port. An ARM processor would be welcome for this device as well - anything to bring the power draw and heat generation down. Also - it would be nice if theyBy the time I am ready to migrate to that, I'll probably appreciate the option for 8 or 16 drive bays.

I got this as an Amazon return for almost half the new retail price. It is very fast via the 10gb interface, of which I wish there were more of because of iSCSI for Proxmox and VMWare. Thunderbolt is very fast and reliable. The only complaint I have is that good NVME flash drives are not more affordable. I only have 5 4TB WD SN850Xs in this thing. I would love to put 5 8TB WD SN850Xs in this. (currently selling for $599.00 each during Black November) but that would cost around $3300.00, which I could do, but still too rich for my taste. I read other folks reviews in the QNAP forums and it seems everyone does RAID 5 on this, which give up way too much expensive storage space, slows the array down and increases write amplification. SSDs a very reliable, but even if I had RAID 5 configured on this or anything else, it is still no substitute for a backup.

Owning 4 other QNAP and multiple QNAP switches, this NAS is easily one of the best in terms of speed, compact size, weight, and overall quality for a very reasonable price. The unit is very quiet and cool to the touch. The unit arrived in pristine condition with packaging and superb construction reminding me of Apple laptops. The trays offer m.2 compatibility prior to transitioning over to E1.S drives. Memory is not upgradeable. The unit has been completely stable with no crashes or random reboots. Overall, I am very impressed with this new product by QNAP. Good job QNAP team.